1840 Farmhouse, 200 amp service.. What they did do is leave a knife switch ahead of the main panel with two 100 amp fuses, plus the breaker box has it's own 200 main breaker.. Since we bought the place , I always noticed if you run a saw, or the vacuum, you can see the lights do a slight but noticeable quick dim.. Well for the heck of it I plugged a digital volt meter into an outlet in the kitchen.. Now I watched,, had 119 volts, had the wife turn the vacuum on , it dropped and stayed at 116 volts while it's running... She was plugged in upstairs on a different circuit.. If I open our refrigerator door I can watch the meter drop a half of volt as the light comes on... Do I have corrosion on a meter leg or a bad neutral or main ground issue some wheres? How about those old fuses? I checked every wire except the mains in my box, all tight.. Couldn't wiggle the mains.. Shouldn't the voltage stay the same as things are powered up? I'm wondering if this is causing us to use more power then needed, thus giving us a higher bill then we should be seeing.. Try to figure where to start.. Another person said we could be at the end of a primary run, thus needing transformer on the pole...I'm all open for what might be the issue here. Be nice to find out we have an issue and can get our power usage down...I always thought our KWH usage was higher then it should be for what's running here..